Nostradamus - Time Travel and Prophecies how could we use time travel? Is time travel a technology that has practical uses? Would changing the past be an option?

Applications for Time Travel and sending messages to the past

Imagine that somewhere in the future we manage to prove that time travel is possible
and we invent the necessary equipment needed to sent travelers and message through time. Then how could we use such science?
Would changing the past be an option? Lets take the following imaginary scenario:

Somewhere far into the future, scientists invent the technology to send messages to the past.
It is part of a science that enables traveling through time and they manage to communicate with
individuals of past centuries. Although these receiving individuals cannot actually see who is sending the
message, they are aware of his presence and can communicate by no other means other than just concentration,
prayer or meditation. True prophecy is taken as proof of successful communication between future and past.

After scientists have established a theory and constructed the necessary machinery it is up to future
politicians and decision makers to decide what to do with it. These people might think that a
well-constructed message could improve the world and that the good such a message would bring weights up against
possible perils and drawbacks.

The type of message that is developed for this purpose is meant to willfully introduce changes into our own past and history.
The object could be to improve the chances of humanity to survive, avoiding the apocalypse or to help the world and steer its development.
Such message could warn for certain dangers, or even be malicious and intended to have 'the enemy' destroy
themselves. The problem however with any such message, is that the consequences are unpredictable as
it's effect will involve generations and there are blind spots.

Time travel might turn out to be an immense powerful technology but with a tremendous potential to backfire.